Case 24 – Elbow Injury
A 12 year old boy presents with a one week history of clicking in the lateral elbow while playing tennis. The clicking is ongoing. He has a history of shoulder pain one year ago and intermittent stiffness at the elbow. No pain at the elbow.
On examination, loss of 10 degrees of flexion. Loss of less than 5 degrees of extension. Crepitus at the radiocapitellar joint with supination and pronation. UCL laxity 0.5+. Remainder of the exam was unremarkable.
Figure 1: Plain AP radiograph of the right elbow. Note the osteochondral defect of the capitellum.
Figure 2: Plain lateral radiograph of the right elbow in full extension. The osteochondral defect is not well visualized.
Figure 3: An axial MRI image of the right elbow. Note the lateral lesion signifying an unstable capitellar osteochondral defect.
Osteochondral defects, or osteochonditis dissecans (OCD), is most often seen in adolescents older than 12 years old who participate in sports involving repetitive loading of the elbow (baseball, tennis, volleyball, weightlifting and gymnastics). Boys are affected more than girls. The capitellum of the dominant arm is affected most often. It can also occur in the knee and ankle.
OCD is a process where a segment of articular cartilage separates from the subchondral bone. The cause of capitellum OCD is thought to be excessive, repetitive valgus compression across the elbow joint with immature articular cartilage. This leads to focal avascular necrosis and subchondral bone changes which in turn leads to the formation of loose fragments.
There should be a high index of suspicion for OCD in adolescent patients complaining of lateral elbow pain. The typical presentation is a young male athlete complaining of pain, tenderness and swelling over the lateral accept of the elbow. In the later stage, there may be loss of extension and intermittent catching and locking of the elbow. Ulnar collateral ligament injuries can also be associated with OCD of the elbow.
Plain anteriorposterior and lateral radiographs are frequently used as a screening method, however they are often insensitive in identifying OCD of the capitellum. If OCD is suspected, additional imaging with CT or MRI is indicated.
It is important to distinguish stable from unstable OCD lesions. Stable lesions are reversible and can heal completely with nonoperative management, whereas unstable lesions require surgical treatment. Stable lesions are characterized by an open growth plate, flattening or radiolucency of the subchondral bone, in an patient with (almost) normal elbow range of motion. Unstable lesions have at least one of the following: a closed growth plate, fragmentation, or restriction of elbow motion 20 degrees or more.
Diagnosis: Unstable capitellar osteochondral defect of the right elbow.
Conservative management: rest for overhead activity, strengthening exercises and NSAIDS. Referral for surgical consult: debridement of the lesion, bone marrow stimulation, removal of fragments, or fragment fixation with biodegradable pinning.
Lucas Nguyen (Dec 9, 2018 – PR ND)